Door operating mechanism for powder hoists



Ill 4) I II II ll/l I III III (5. A. CHADWICK EI'AL DOOR OPERATING MECHANISM FOR POWDER HOISTS Filed March 10, 1944 4 She'ets-Sheet 1 FIE. I v

INVENTORS 650065 A. MIDI/6K BY PMLA If. BIROIMRD ATT EY Get. 26, 194. s. A. CHADWICK EI'AL 2,452,035

DOOR OPERATING MECHANISM FOR POWDER HOISTS Filed March 10, 1944 4 Sheets-Sheet 3 mm m was. I m

INVENTORS GEORGE a. GHADIVIGK PHIL/A amaumo 0% 1943- e. A. CHADWICK EI'AL 2,452,935

DOOR OPERATING MECHANISM FOR POWDER HOISTS Filed March 10, 1944 4 Sheets-Sheet 4 INVEN1ORS GEORGE A. GHfiDW/CK BY PHIL/44$ H GIROUARD ATTOR Patented Oct. '26, 1948 DOOR OPERATING MECHANISM FOR I POWDER HOISTS George A. Chadwick, Den-on,- Mich and Philias H. Girouard, Washington, D. 0.

Application March 10, 1944, Serial No. 525,964

4 Claims. (01. 89-46) (Granted nnderthe act of March 3. 1883, as mended 'April so, 1928; 310 o. G. 157) The following disclosure relates to door closing and sealing means, and is particularly adapted for operating and sealing a swinging door at the upper end of a powder hoist for powder bags used in hea guns.

Th several objects of the device herein described are:

(a) To provide a means for closing the upper end of the powder trunk, while the powder car is in motion;

(b) To provide a flame-tight seal for the closing means;

(c) To provide a means for transferring the powder bags from the powder car trays to the gun loading tray;

(d) To provide an automatic means of controlling the closing means and the sealing means so that each operation occurs in th proper sequence.

The device is illustrated in its preferred form in the accompanying drawings, in which:

Fig. 1 is an end view of the door in open position, partly in section, with a. cross-sectional view of the upper end of the powder hoist trunk and of the powder cars therein, as well as the gun loading tray onto which the powder bags are rolled from the powder cars,

Fig. 2 is a side view of the door in closed position and the sealing dogs in position to seal the door tightly in place,

Fig. 3 shows the detail structure and arrangement of the sealing dogs and the mechanism which operates them, and

Fig. 4 is a schematic illustration of the hydraulic system used in the control of the operating means for the opening and closing of the door and for the movement of the sealing dogs in the proper sequence with relation thereto.

The closing means illustrated consists of a swinging door I, hinged at its lower end at 39 and fixed frame 36, thereby compressing the door gasket 41 and forming a flame-tight seal. The dogs are connected by an operating linkage to a second hydraulic cylinder l2, as shown more clearly in Fig. 3.

The means for controlling the operation of the door and the dogs consists of the hydraulic system shown schematically in Fig. 4. It comprises a pump it driven by an electric motor IS, a control valve 24, a door operating cylinder 2, a dog operating cylinder I2, and interconnecting piping as shown.

The operation of the hydraulic circuit is as follows: i

To open the door, the door control valve handle 21 is shifted to and held by hand in its upper position. Oil under pressure will then be ported from the pump it through pipes l9 and 23, control valve 24, and pipe 29 to the lower end of the do operating cylinder l2. The piston II will move upward, thereby rotating the dog operating linkage and unlocking the door. As soon as the dogs 50 have been rotated sufficiently to clear the door, the dog operating cylinder piston H will uncover a port for a pipe line 30 to convey the pressure to the upper end of the door operating cylinder 2. The door operating piston 5 will then move down against the pressure of spring 34 and open the door. When the door is opened, the operator releases the handle of the door control valve and it is returned to its neutral position by spring 26, thus unloading the pump discharge through the valve to the expansion tank I! via pipes 22 and 2|. An overload relief valve 20 i used in the line between the pump discharge pipe 2|.

operated by a hydraulic cylinder 2. When the door is opened, the space between the powder car 4i and the gun loading tray 35 willbe bridged by the door, as shown in Fig. 1. It should be noted also that the port (defined by the door framing 36 of the trunk 40) and the hinge 39 for the door i is located at a higher elevation than the receiv- After the powder bags have-been removed from the powder car M (the car, as shown, will stop in two successive positions in order to unload both trays 42 and 43), the door control valve will be moved to and held manually in its lower position.

' Oil under pressure from the pump will then be ported through the door control valve to the lower end of the door operating .cylinder 2 through pipe 33. The door operating piston 5 will be moved upward, thereby closing the door. Near the end of the upward travel of the door operating piston,

a port will be uncovered,.and the pressure will be I ported via. pipe 32 to the door operated Valve 13.

However, this pressure will be blocked by the valve l3 until the door is almost completely closed, at which time the pressure will be'ported move downward, thereby rotating the dog operatpipe l9 and return ing linkage and dogging the door. when the door is thus locked, the door control valve is released by the operator and is returned by spring 28 to its neutral position, thus unloading the pump discharge to th expansion tank through plpesi22= and-2i.

The purpose of the door operated valve 63 is to prevent the porting of pressure for closing of the.

dogs until the door is almost completely closed. Theoretically, the center port in the door operating cylinder will perform this function, but due to the actual arrangements of the door operating cylinder with respect to th door, .-the movement.

the door opens the valve; the door operated valve.

will therefore be opened only when the upperend of the door is very near its completely closed position.

The spring at in the door operating cylinder is provided to approximately counterbalance the door.

A relief valve 20 is provided in the hydraulic circuit to limit the maximum pressure in the system. The dog operating piston II is arranged for equal areas on both sides of the cylinder in order to have equal forces for opening and closing the dogs (the toggle linkage 6, l for operating the dogs moves past the dead center position in order to provide a more positive lock) The control valve is arranged to equalize the pressures in opposite sides of the cylinders when released into neutral position so as to permit 4 including a trunk having a port therein, a hoistmanual operation of thedog linkage and the door in the event of failure of the hydraulic system, or the power supply to the electric motor.

Fig. 1 shows the powder car 4| in its uppermost position with the lower powder tray 43 tilted to discharge the powder bag hoisted on it and thereby permit it to roll down the door I into the gun loading tray 35. The door operat-,

ing cylinder 2 is pivoted at 46 and the pipes 30, 32 and 33 have swivelled connections at this pivot to the portions connected to-a'nd movable with the cylinder. r

The dog operating cylinder I2 is pivotedat 59 where pipes 29, 30 and 3| have a swivelled connection to their movable portions incorporated in the body of the cylinder i2.

The details of the dog operating mechanism may be seen in Fig. 3. Thedogs 50 are pivoted at 38 and are all connected to move in unison by the links 54, 48, 55 and 56 and the bell cranks 5|, 52 and 53. Bell crank 52 has integral'lever 31 connected for operation to the linkage B, 1 which is actuated by piston rod 9 pivoted thereto at 58 in Fig. 3. The piston rod may be connected to the pivot 51 between links 6 and 1 as shown in the schematic diagram, and the link 6 may be connecteddirectly tofone'of the, dog levers as shown in Fig. 4. I

The dogs 50 operate against the wedges 6i, as shown in Fig. 2, to press the door tightly against the fixed frame 36, compressing the gasket 41 all the way around the door, thus forming a flametight seal. Suitable clearance isprovided in the hinges 39 to permit this. p

Various modifications in form and arrangement of the present device may be made without de- 4 1 parting from the scope oi! this invention as de fined by the appended claims.

The invention described herein may be manu factured and used by r for the Government 0 1; the United States of America for governmenta purposes without the payment of any royaltie. thereon or therefor.

What isolalmed is:

1. In a gunemplacement, an ammunition hols 1Q including, a trunk and a car, a gun loading tray a door hinged at its bottom edge to the trunk am so constructed and arranged as to substantial]: bridge the space between the trunk andlahe loading tray when they door is open, fluid PI'CSSUI'i mechanism arranged to operate the door, sealing means arranged to secure the door to the trunk fluid pressure mechanism arranged to operate the sealing means, and a fluid pressure system including said mechanisms for sequently actuating said mechanisms both to release the sealing means prior to opening the door and to close thr door prior to fastening the sealing means.

2. In a gun emplacement, an ammunition hoist including a trunk and a hoisting car, a gun loading tray, a door hinged at its bottom edge to th! trunk and so constructed and arranged as tc substantially bridge the space between the cal and the loading tray when the door is open; 2 dog coacting with the door to secure the door to the trunk, a dog operating mechanism actuated by a fluid under pressure, a door operating mechanism actuated by a fluid under pres- .sure, and a fluid pressure system including a control valve and said mechanisms arranged to sequentially actuate the dog operating mechanism prior to the door operating mechanism in opening the door and the door operating mechanism prior to the dog operating mechanism inclosing the door.

3. In agun emplacement; an ammunition hoist to hold the door in sealing relation with respect to said port; a fluidjpressure system comprising a dog operating mechanism, a door operating mechanism, means including a control valve for directing a fluid under pressure to first actuate one of said mechanisms, and means including said first actuated mechanism for further direct- ,ing the fluid to thereafter actuatethe other of said mechanisms, whereby the dog operating mechanism releases the dog prior to the operation of the door operating mechanism in opening the door and the door operating mechanism closes the door prior to the operation of the dog operating mechanism in fastening the dog to seal off the said port. 5 4. In a gun emplacement. an ammunition hoist including a trunk and a hoisting car therein with a tiltable tray, a gun loading tray, a door on the trunk with a hinge at the bottom edge of the door located higher than loading tray, the door being so constructed and arranged as to substantially 9 bridge the space between the tiltable tray and the wedge on the outer side of and near an edge of 'aesaoss d the door, a dog pivotaliy attached to the trunk and movable against the wedge to press the gasket against the frame to form a flame tight seal, a dog operating piston and coacting cylinder provided with an outlet which is uncovered by the piston near the end of the dog releasing stroke, a door operating piston and coacting cylinder provided with an outlet which is uncovered by the piston near the end of the door closing stroke, the door operating piston and cylinder serving as a support for the door when open and having a spring counterbalancing the weight of the door, a source of fluid under substantially constant pressure, means including a single manually operable control valve to direct the fluid to one side of the dog operating piston to release the dog, means including the dog operating cylinder outlet to thereafter further direct the fluid to one side of the door operating piston to open the door, means including the control valve to direct the fluid to the opposite side REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 564,474 Cowles July 21, 1896 1,105,813 Meigs et al Aug. 4, 1919 1,371,738 Dawson et'al Mar. 15, 1921 1,392,583 Lee et al Oct. 4, 1921 1,465,990 Lee et al. Aug. 28, 1923 1,849,385 Sekulski Mar. 15, 1932 2,260,080

Lane Oct. 21, 1941 

